1. Field of the Invention
This invention relates to an ophthalmic measuring apparatus for use in ophthalmic clinics or the like.
2. Related Background Art
A cornea shape measuring apparatus according to the present invention is such that a beam of light from a light source is imaged on the cornea, this image of the light source is observed through a monitor or a lens, the focus and image position of this image of the light source are adjusted to thereby effect alignment, and a measurement button is depressed to start the measurement of the cornea shape.
To accomplish highly accurate cornea shape measurement, it is necessary to effect the alignment of the apparatus accurately. Heretofore, however, the judgment of the termination of the alignment of the apparatus has depended on visually recognizing the image of the light source and therefore, such judgment differs for each time of measurement due to differences between individual examiners or even by the same examiner and thus, the measured value becomes unstable. Also, to effect measurement, there is the cumbersomeness that the measurement starting button must be newly depressed, and skill is required for the operation of the apparatus.
Japanese Laid-Open Patent Application No. 1-91831 discloses a cornea shape measuring apparatus in which when cornea shape measurement is to be effected by the use of the cornea reflection images of four light sources for measurement around an optical axis, the setting of the quantity of light is automatically effected when it is recognized that the number of the cornea reflection images has reached a predetermined number, whereafter the starting of the measurement is confirmed.
Also, Japanese Laid-Open Patent Application No. 2-220626 discloses a construction in which when cornea shape measurement is to be effected by the use of the cornea reflection image of a light source for measurement, an alignment state is detected from the quantity of the cornea reflected light and the cornea reflection image of the light source for measurement is introduced when the quantity of said light is a predetermined value or greater.